Wastewater (also known as storm water and sewer) pipelines are an essential part of the infrastructure of modern populated areas. These pipelines must be maintained, and this requires periodic inspection of every linear foot of the wastewater pipeline per federal or regulatory mandates. For example, conventional sewerage systems may be periodically inspected for the presence of cracks and other anomalies by the deployment of waterproof video equipment which is mounted on a mechanical device. The device can be remotely operated in a motorized fashion to traverse the interior of the wastewater pipe, or may be alternatively towed on a suitable carriage.
Remotely-operated inspection apparatuses, commonly known as “transporters”, may be used for pipeline inspections. Transporters may be particularly useful in the inspection of smaller diameter pipe which is too small for direct inspection. Transporters may carry video cameras or sonar, radar or other sensing equipment along the interior of the pipe to allow personnel to view cracks and other imperfections in the pipe. Wheeled transporters are also used in the relining of pipes, where the transporter carries ultraviolet lights designed to “cure” or harden plastic/polymer lining (sleeve) material after inflation inside the pipe. After relining occurs, the openings of lateral pipes are occluded by the new lining sleeve. A third type of wheeled transporter, carrying rotary cutting equipment, is used to locate and reinstate the lateral openings to the relined mainline.
Many transporters may utilize multiple drive axles fitted with wheels which are designed to maximize traction of the wheels against the interior surface of the pipe. The wheels may include solid rubber or polyurethane traction (tread) surfaces, which are advantageous in that they cause negligible damage to the interior of the pipe. However, rubber and polyethylene traction surfaces do not provide sufficient traction to allow operation of transporters beyond a distance defined by the forces acting on the transporter, greases and other slick coatings common in active wastewater pipes, and more particularly the friction coefficients at the tire-to-pipe interfaces. Alternatively, the transporter wheels may be constructed by bonding carbide grit to the tread surface of a hub made of metal or other material. Carbide grit traction sections may provide superior traction to allow further penetration of the transporter through a section of pipe. However, carbide grit traction sections may have the attendant disadvantage of causing wear relatively quickly to the interior surface of the pipe. Moreover, conventional carbide grit transporter wheels typically have a shorter useful life.
Accordingly, there is an established need for a pipe transporter traction wheel which is suitable for mounting on a pipe transporter, has superior traction capability, has a prolonged tread life, prevents or minimizes damage or wear to the interior surface of a pipe in which the pipe transporter is deployed, and/or addresses other needs.